Attachment of some sensors of a vehicle, such as exhaust pressure sensors, requires precise orientation of a tubing (or pipe) assembly to align the sensor with a fixed base (e.g., a boss) that is welded to an exhaust passage. Typically, the tubing assembly includes a press washer having a protrusion that matches a notch (e.g., a groove) in the fixed base, such that the press washer fits into the fixed base in a single orientation. Such an alignment constraint adds complexity to the sensor installation process. If the resulting joint between the tubing assembly and fixed base is misaligned, stress on the tubing assembly may be increased, leading to sensor degradation. In one example, if the tubing assembly does not align with other sensor components, the tubing may be torqued to force the alignment, putting strain on the sensor joint. As another example, the misalignment may press the exhaust sensor into other vehicle components, putting strain on the tubing assembly and the sensor joint that may degrade the sensor over time. As a result, to correct the misalignment, the fixed base may be removed, realigned, and re-welded, which increases the time and cost of sensor installation.
The inventors herein have recognized that by eliminating the opportunity for misalignment, sensor installation times and costs may be reduced. In one example, the issues described above may be addressed by a system comprising: a tapered pipe having a flange at its wider end; a nut assembly having a head, a cylindrical externally threaded bottom extending down from the head, and a tapered inner cavity adapted for positioning over the tapered pipe; and a boss having a threaded inner cavity, adapted to engage with the threaded bottom of the nut assembly, and an engagement cavity extending below the threaded inner cavity adapted to receive the flange. In this way, exhaust sensor joint alignment constraints may be reduced.
As one example, the nut assembly may be positioned around the tapered pipe, and the tapered pipe and the nut assembly may be freely rotatable around a common central axis. The tapered pipe and the boss may form a seal when the flange of the tapered pipe is inserted into the engagement cavity of the boss, the threaded bottom of the nut assembly is mated with the threaded inner cavity of the boss, and a bottom-most end of the threaded bottom presses the flange into the engagement cavity. Once the flange is pressed into the engagement cavity of the boss, further rotation of the tapered pipe may be prevented, with the tapered pipe held firmly in place by a downward force from the nut assembly. In this way, the tapered pipe may be inserted into the boss at any rotational orientation (with respect to the common central axis) and adjusted to align with other vehicle components until the nut assembly is torqued and pushes against the flange of the tapered pipe, eliminating re-welding of the boss due to joint misalignment. As a result, exhaust sensor installation times and costs may be reduced. Furthermore, due to the taper of the pipe and the tapered inner cavity of the nut, the tapered inner cavity of the nut may not contact outer walls of the pipe during the torquing process, reducing stress put on the pipe during sensor installation and thereby reducing sensor degradation.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.